Help with a Western Electric Rectifier Please

I bought a Western Electric "Rectifier" and would like to know what it's purpose is and whom would use it. It is not tube driven. It's self contained in a metal case and has a capacitor, transformer (and others) and a power cord along with two alligator clips (black and red). Any help would be appreciated, I'm a novice on electronics. Is this an audio or telephone related item?
If no one here knows what a rectifier is, what board should I try?
I'm certain there are many in "here" that know what a "rectifier" is. However: What you have described is NOT. A rectifier(either full or half wave) will either be comprised of a Selenium or copper oxide stack, diode bridge or tube that converts AC to DC voltage. A transformer and capacitor in a box would constitute(possibly) part of a power supply. Had you included a part number, or some identifying information- you may have received a reply from someone familiar with WE parts. It sounds like an outboard power supply for testing of some nature, especially considering the red and black wires.
YES- It is a DC output power supply. The output(secondary) of the transformer is changed via the taps. I'm guessing those are instructions on the door? That KS-5663-L7 is the model number. You might try contacting WE with that model number for possible further info: (